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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Sun, 24 Sep 2023 02:15:29 +0200
Message-ID: <CACRpkdbHOa=59DnQzZRV0BrDx0yxm97JjaR0GaeG3jywW0bRBg@mail.gmail.com>
Subject: Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by
To:     Kees Cook <keescook@chromium.org>
Cc:     Bartosz Golaszewski <brgl@bgdev.pl>,
        Andy Shevchenko <andy@kernel.org>, linux-gpio@vger.kernel.org,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, linux-hardening@vger.kernel.org
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On Fri, Sep 22, 2023 at 7:52=E2=80=AFPM Kees Cook <keescook@chromium.org> w=
rote:

> Prepare for the coming implementation by GCC and Clang of the __counted_b=
y
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUND=
S
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct linereq.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/c=
ounted_by.cocci
>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

That's neat!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij